Shatner spoke out about criticism that suggested he wasn't making enough of an effort to attend his 'Star Trek' co-star's Sunday funeral.

William Shatner kept true to his word to use his Twitter page as a place to pay tribute Sunday to Leonard Nimoy, who died Feb. 27 at the age of 83.

Shatner shared memories of his Star Trek co-star and answered questions posted about Nimoy by Twitter users. Shatner had announced Saturday that he would be unable to attend Nimoy's Sunday funeral because of a charity commitment.

When asked what Shatner most respected about Nimoy, he replied, "His compassion and dedication." He also said that, unlike Nimoy's Spock character, the actor himself was "warm and loving."

Some Twitter users criticized Shatner for not finding a way to get from Florida, where his charity event took place Saturday night, to the memorial service in Los Angeles.

"I can't imagine Shatner not moving heaven & earth to get to Nimoy's funeral," one Twitter user wrote. Another person tweeted that she was "tearing up because William Shatner can't make it to Leonard Nimoy's funeral.

Shatner addressed the backlash, explaining that he was unable to find a flight to LAX that could accommodate his schedule. He even posted the front page of Sunday's New York Daily News, which referred to him with the headline, "Captain Jerk!"

"I chose to honor a commitment I made months ago to appear at a charitable fundraiser," Shatner wrote Sunday. "A lot of money was raised. So here I am; tell me off." He pointed out that his two daughters would be attending the funeral.

Shatner also criticized radio host Todd Schnitt's claim that he should be able to hop on a private jet after his charity function. "I must have missed your email about underwriting the arrangement and payment for this," Shatner wrote.

Several tweets can be seen below.

One of the other misconceptions seems to be that folks think flights to LAX occur all night long.